Emergent Fossilization by Brian MacWhinney

Emergent Fossilization

The following hypotheses attempt to capture the Age of Arrival (AoA) and fossilization patterns using clearly stated mechanisms for processing and learning.

1. The lateralization hypothesis (Lenneberg, 1967): Lenneberg claimed that AoA effects arise from maturational changes in the brain related to lateralization of function. The idea here is that the massive changes that occur at puberty serve to terminate the language learning abilities of the child by finalizing the process of lateralization. However, this account has not received much empirical support.

2. The neural commitment hypothesis (Lenneberg, 1967): Lenneberg proposed that another mechanism for AoA effects involves a progressive maturational commitment of language areas to linguistic functioning. This hypothesis would claim that some specific brain region or set of regions is undergoing commitment in parallel with the period during which AoA effects are demonstrated for learners.

3. The parameter-setting hypothesis (Flynn, 1996): Generative linguists such as Flynn have proposed that first language learning depends on a process of parameter setting specified by universal grammar (UG). Some UG researchers have favored a second model that holds that the parameters of UG that were available to the child are no longer available to the adult older second language learner.

4. The metabolic hypothesis (Pinker, 1994): Pinker has proposed an innovative account of AoA effects based on notions from cognitive neuroscience and evolution. He suggests (p.293) that “a decline in metabolic rate and the number of neurons during early school-age years” is a probable cause of the loss of language-learning ability. However, there is no evidence for any overall loss in metabolic activity of the type Pinker is suggesting.

5. The reproductive fitness hypothesis (Hurford & Kirby, 1999): They reason that, over the course of human evolution, the attainment of complete fluency in a first language was a major determinant of reproductive fitness. If a child had not successfully acquired language by the age of sexual maturity, they would not be as attractive to a sexual partner and would therefore be less likely to produce offspring. Conversely, those who had acquired a high level of language ability would be highly attractive and would reproduce…The wide range of individual differences in successful mastery of a language after early children does indeed suggest that a variety of fairly recent evolutionary pressures have been operating to produce the observed population diversity.

6. The aging hypothesis (Barkow et al., 1992): Proponents of this hypothesis believe that as they age, most people begin to experience a marked slowdown in metabolic activity, energy, and flexibility. Core cognitive functions such as the storage of new memories and the retrieval of old memories can be disrupted by degeneration in the hippocampus and temporal lobe…Aging is certainly not going to account for all age-related effects, since it tells us nothing about changes before 45. However, it is clearly a contributory factor to some fossilization.

7. The fragile rate hypothesis (Birdsong, 2005): Birdsong suggests that, with increasing age, learners may have more problem acquiring irregular forms as opposed to regular forms. He suggests that irregular forms may include not only words with irregular inflections, but also irregular use of particles and prepositions in phrasal verbs. Birdsong seeks to ground the decline in learning of irregulars on neuroanatomical changes in the parts of the brain subserving the declarative memory system. There is little evidence to support his hypothesis.

8. The starting small hypothesis (Elman, 1993): Newport (1990) argues that “language learning declines over maturation precisely because cognitive abilities increase.” The idea is that children have a smaller short-term memory span and that this shorter span makes it more difficult for them to store large chunks of utterances as formulaic items. As a result, children are forced to analyze language into its pieces.

9. The entrenchment hypothesis (Marchman, 1992): Those who advocate the entrenchment hypothesis believe that when we practice a given skill thousands of times, we soon find that it has become automated or entrenched. The more we continue to practice that skill, the deeper the entrenchment and the more difficult it becomes to vary or block the use of the skill. Entrenchment occurs in neural networks when a high frequency pattern is presented continuously in the input training data.

10. The entrenchment and balance hypothesis (MacWhinney, 2005): According to MacWhinney, catastrophic interference can be solved by systems that emphasize the lexical and item-based nature of second language learning. Moreover, these lexically-grounded systems can also illustrate another important aspect of second language learning. This is the parasitic nature of L2 learning when L2 is already well consolidated. Parasitism occurs because the L1 form is already well consolidated and entrenched by the time the learner tries to add the L2 form to the map. But what happens when both L1 and L2 are acquired simultaneously during childhood…In this way, simultaneous bilingual acquisition tends to minimize the misleading effects of transfer and parasitism.

11. The social stratification hypothesis (MacWhinney, 2006): Acculturation during adulthood involves a far greater diversity of situations. In some cases, immigrants may marry into the L1 community, thereby guaranteeing basic acceptance and access to input. However, even in these cases, they will not be treated in as supportive a manner as a parent treats a child. When they are overtly corrected, they will feel a certain loss of prestige that can strain social relations. Outside of marriage, L2 acculturation may succeed through work groups and casual social groups.

12. The compensatory strategies hypothesis (MacWhinney, 2006): The variance we find in adult L2 attainment must certainly be explained in large part by variation in the social contexts facing, immigrants and the ways in which they deal with these contexts socially. However, even in unfavorable social situations, learners can make use of compensatory learning strategies. These strategies are designed to directly combat the effects of increased L1 entrenchment, as well as the effects of biological again. There are at least three major strategies: input maximization, recoding, and resonance.

i.               Input maximization: receiving input from books, dictionaries, movies, lectures, practice using the language as much as possible.  

ii.              Recoding: representing the new word orthographically.

iii.            Resonance: establishing a series of associative relations between words and meanings that can allow the learner to maintain a vivid image of the word until the relations are consolidated.

References:

Barkow, J., Cosmides, L. and Tooby, J. (eds.) (1992) The Adapted Mind:         Evolutionary Psychology and the Generation of Culture. New York: Oxford University Press

Birdsong, D. (2005) Interpreting age effects in second language acquisition. In J.F.             Kroll and A.M.B. deGroot (eds) Handbook of Bilingualism:   Psycholinguistic Approaches (pp. 109-127). New York: Oxford University       Press.

Elman, J. (1993) Incremental learning, or the importance of starting small. Cognition 48, 71-99.

Flynn, S. (1996) A parameter-setting approach to second language acquisition. In W.C. Ritchie and T.K. Bhatia (eds.) Handbook of Second Language       Acquisition (pp. 121-158). San Diego: Academic Press.

Hurford, J. and Kirby, S. (1999). Co-evolution of language size and the critical       period. In D. Birdsong (ed.) Second Language Acquisition and the Critical   Period Hypothesis (pp. 39 – 63). Mahwah, NJ: Lawrence Erlbaum        Associates.

Lenneberg, E. H. (1967) Biological Foundations of Language. New York: Wiley. 

MacWhinney, B. (2005) A unified model of language acquisition. In J.F. Kroll and A.M.B. deGroot (eds) Handbook of Bilingualism: Psycholinguistic         Approaches (pp. 49-67). New York: Oxford University Press.

MacWhinney, B. (2006) Emergent Fossilization. In Han, Z. & Odlin, T. (eds)            Studies of Fossilization in Second Language Acquisition. Clevedon:      Multilingual Matters.

Marchman, V. (1992) Constraint on plasticity in a connectionist model of the         English past tense. Journal of Cognitive Neuroscience 4, 215-234.

Pinker, S. (1994) The Language Instinct. New York: William Morrow.